directional data; likelihood rule; classification; von Mises distributions; unknown mean directions; known common concentration parameter; plug-in rule; moment generating function
The paper deals with two Mises distributions on the circle with unknown mean directions and a common concentration parameter that is known. The likelihood rule and the plug-in rule are examined. For the statistic of the plug-in rule, the moment generating function is given and a method of obtaining the moments is proposed.
 H. Bateman A. Erdélyi: Higher transcendental functions
. vol. 2, McGraw-Hill 1953. MR 0058756